A system for simultaneously inspecting the frontsides and backsides of
semiconductor wafers for defects is disclosed. The system rotates the
semiconductor wafer while the frontside and backside surfaces are
generally simultaneously optically scanned for defects. Rotation is
induced by providing contact between the beveled edges of the
semiconductor wafer and roller bearings rotationally driven by a motor.
The wafer is supported in a tilted or semi-upright orientation such that
support is provided by gravity. This tilted supporting orientation
permits both the frontside and the backside of the wafer to be viewed
simultaneously by a frontside inspection device and a backside inspection
device.